Motorized vehicle having forward and backward differential structure

ABSTRACT

A motorized vehicle includes a plurality of single-direction thrust bearings mounted between each of the two rear wheels and the propeller shaft. The single-direction thrust bearings located at one rear wheel is used to drive the motorized vehicle to move forward, and the single-direction thrust bearings located at the other rear wheel is used to drive the motorized vehicle to move backward. Thus, when the two rear wheels are subjected to a drag and cannot be rotated with the propeller shaft synchronously, the single-direction thrust bearings will idle, thereby producing a differential effect.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a motorized vehicle, and moreparticularly to a motorized vehicle having a forward and backwarddifferential structure.

[0003] 2. Description of the Related Art

[0004] A conventional motorized vehicle comprises a differential mountedon the transmission gear of the gear box. The differential consists of abevel gear set. The power of the motor is reduced by the reductionmechanism. Then, the reduced power is transmitted by the transmissiongear of the gear box and the bevel gear of the differential to thepropeller shafts at the left and right sides, to drive and rotate thewheels at the left and right sides. When the motorized vehicle isturned, the turning diameter of the wheel at the inner side is shorterthan that of the wheel at the outer side, so that the differentialconsisting of the bevel gear set is used to balance the difference ofthe rotation speed between the wheel at the inner side and the wheel atthe outer side.

[0005] However, the conventional differential consisting of a bevel gearset has a complicated construction, thereby increasing costs offabrication, and thereby causing inconvenience in assembly andmaintenance.

SUMMARY OF THE INVENTION

[0006] The primary objective of the present invention is to provide amotorized vehicle having a forward and backward differential structure.

[0007] Another objective of the present invention is to provide amotorized vehicle, wherein when the two rear wheels are subjected to adrag or resistance and cannot be rotated with the propeller shaftsynchronously, the single-direction thrust bearing will idle, therebyproducing a differential effect.

[0008] A further objective of the present invention is to provide amotorized vehicle, wherein the single-direction thrust bearings locatedat one of the two rear wheels is used to drive the motorized vehicle tomove forward, and the single-direction thrust bearings located betweenthe other rear wheel is used to drive the motorized vehicle to movebackward.

[0009] A further objective of the present invention is to provide amotorized vehicle having a differential structure which can replace theconventional differential consisting of a bevel gear set, therebyreducing costs of fabrication, and thereby simplifying the construction.

[0010] In accordance with the present invention, there is provided amotorized vehicle, comprising:

[0011] two rear wheels;

[0012] a propeller shaft mounted on the two rear wheels and having twoends; and

[0013] a plurality of single-direction thrust bearings mounted betweeneach of the two rear wheels and the propeller shaft, wherein:

[0014] the single-direction thrust bearings located between one of thetwo rear wheels and a first end of the propeller shaft has a rotationdirection opposite to a normal rotation direction of the propeller shaftto drive the motorized vehicle to move forward; and

[0015] the single-direction thrust bearings located between the otherone of the two rear wheels and a second end of the propeller shaft has arotation direction opposite to a reverse rotation direction of thepropeller shaft to drive the motorized vehicle to move backward.

[0016] Further benefits and advantages of the present invention willbecome apparent after a careful reading of the detailed description withappropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a partially exploded perspective view of a motorizedvehicle in accordance with the preferred embodiment of the presentinvention;

[0018]FIG. 2 is a front plan cross-sectional assembly view of themotorized vehicle as shown in FIG. 1;

[0019]FIG. 3 is a top plan cross-sectional assembly view of themotorized vehicle as shown in FIG. 1;

[0020]FIG. 4 is a perspective assembly view of the differentialstructure of the motorized vehicle in accordance with the preferredembodiment of the present invention;

[0021]FIG. 5 is an exploded perspective view of the differentialstructure of the motorized vehicle in accordance with the preferredembodiment of the present invention;

[0022]FIG. 6 is a side plan cross-sectional view of the differentialstructure of the motorized vehicle as shown in FIG. 4;

[0023]FIG. 7 is a schematic top plan operational view showing theturning state of the motorized vehicle in accordance with the preferredembodiment of the present invention;

[0024]FIG. 8 is a side plan cross-sectional assembly view showing thenormal transmission state of the motorized vehicle in accordance withthe preferred embodiment of the present invention; and

[0025]FIG. 9 is a side plan cross-sectional assembly view showing thedifferential state of the motorized vehicle in accordance with thepreferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Referring to the drawings and initially to FIGS. 1-6, a motorizedvehicle 10 having a forward and backward differential structure inaccordance with the preferred embodiment of the present invention has arear portion provided with a propeller shaft 11 having two ends eachprovided with a catch flange 12, a keyway 13 (see FIG. 6), and an outerthread 14 (see FIG. 6).

[0027] Each of the two ends of the propeller shaft 11 is provided with abearing cap 20, two single-direction thrust bearings 30, a bearing seat40, and a fixing member 50.

[0028] The bearing seat 40 is formed with a plurality of screw bores 41.The bearing cap 20 is formed with a plurality of through holes 21. Themotorized vehicle 10 further comprises a plurality of locking screws 22each extended through a respective one of the through holes 21 and eachscrewed into a respective one of the screw bores 41, thereby fixing thebearing cap 20 on the bearing seat 40.

[0029] Each of the two single-direction thrust bearings 30 is mountedbetween the bearing seat 40 and the propeller shaft 11. Each of the twosingle-direction thrust bearings 30 has an inner race formed with aninner keyway 31.

[0030] The motorized vehicle 10 further comprises a first key 32 securedin the inner keyway 31 of each of the two single-direction thrustbearings 30 and the keyway 13 of the propeller shaft 11, so that each ofthe two single-direction thrust bearings 30 is combined with thepropeller shaft 11.

[0031] Each of the two single-direction thrust bearings 30 has an outerrace formed with an outer keyway 310. The bearing seat 40 has two sideseach formed with a keyway 42. The motorized vehicle 10 further comprisestwo second keys 320 each secured in the outer keyway 310 of a respectiveone of the two single-direction thrust bearings 30 and the keyway 42 ofthe bearing seat 40, so that each of the two single-direction thrustbearings 30 is combined with the bearing seat 40.

[0032] One of the two single-direction thrust bearings 30 is rested onand limited by the catch flange 12 of the propeller shaft 11 and thebearing cap 20.

[0033] The fixing member 50 is secured on the propeller shaft 11 and isrested on the other one of the two single-direction thrust bearings 30.Preferably, the fixing member 50 is formed with an inner thread 51screwed on the outer thread 14 of the propeller shaft 11, so that thefixing member 50 is fixed on the propeller shaft 11.

[0034] The bearing seat 40 has a periphery provided with a fixing board43, and the motorized vehicle 10 further comprises two rear wheels 60each secured on the fixing board 43 of the respective bearing seat 40.

[0035] The fixing board 43 of the bearing seat 40 is formed with aplurality of through holes 44. Each of the two rear wheels 60 is formedwith a plurality of through holes 62. The motorized vehicle 10 furthercomprises a plurality of locking bolts 45 each extended through arespective one of the through holes 44 of the fixing board 43 of thebearing seat 40 and a respective one of the through holes 62 of therespective rear wheel 60, so that each of the two rear wheels 60 isfixed on the fixing board 43 of the respective bearing seat 40.

[0036] In addition, the two single-direction thrust bearings 30 locatedat a first end of the propeller shaft 11 has a rotation directionopposite to the normal rotation direction (when the motorized vehicle 10is moved forward) of the propeller shaft 11 to drive the motorizedvehicle 10 to move forward, while the two single-direction thrustbearings 30 located at a second end of the propeller shaft 11 has arotation direction opposite to the reverse rotation direction (when themotorized vehicle 10 is moved backward) of the propeller shaft 11 todrive the motorized vehicle 10 to move backward.

[0037] In operation, referring to FIGS. 7-9 with reference to FIGS. 1-6,when the motorized vehicle 10 is turned around, the rear wheel 60 at theinner side cannot be rotated with the propeller shaft 11 synchronously.At this time, the single-direction thrust bearing 30 idles, therebyproducing a differential effect, thereby reducing the turning diameterof the motorized vehicle 10, and thereby reducing wear of the rearwheels 60.

[0038] Accordingly, the single-direction thrust bearings located at oneof the two rear wheels is used to drive the motorized vehicle to moveforward, and the single-direction thrust bearings located between theother rear wheel is used to drive the motorized vehicle to movebackward. Thus, when the two rear wheels are subjected to a drag orresistance and cannot be rotated with the propeller shaft synchronously,the single-direction thrust bearing will idle, thereby producing adifferential effect.

[0039] In practice, the motorized vehicle is driven by the two rearwheels. For example, the single-direction thrust bearings located at theleft rear wheel is used to drive the motorized vehicle to move forward.At this time, the single-direction thrust bearings located at the rightrear wheel idles. On the contrary, the single-direction thrust bearingslocated at the right rear wheel is used to drive the motorized vehicleto move backward. At this time, the single-direction thrust bearingslocated at the left rear wheel idles. Thus, the single-direction thrustbearings mounted on the two rear wheels form a differential effect whenthe motorized vehicle is turned or driven on an abnormal road condition.

[0040] Although the invention has been explained in relation to itspreferred embodiment(s) as mentioned above, it is to be understood thatmany other possible modifications and variations can be made withoutdeparting from the scope of the present invention. It is, therefore,contemplated that the appended claim or claims will cover suchmodifications and variations that fall within the true scope of theinvention.

What is claimed is:
 1. A motorized vehicle, comprising: two rear wheels;a propeller shaft mounted on the two rear wheels and having two ends;and a plurality of single-direction thrust bearings mounted between eachof the two rear wheels and the propeller shaft, wherein: thesingle-direction thrust bearings located between one of the two rearwheels and a first end of the propeller shaft has a rotation directionopposite to a normal rotation direction of the propeller shaft to drivethe motorized vehicle to move forward; and the single-direction thrustbearings located between the other one of the two rear wheels and asecond end of the propeller shaft has a rotation direction opposite to areverse rotation direction of the propeller shaft to drive the motorizedvehicle to move backward.
 2. The motorized vehicle in accordance withclaim 1, wherein each of the two ends of the propeller shaft is providedwith a bearing cap, two single-direction thrust bearings, a bearingseat, and a fixing member.
 3. The motorized vehicle in accordance withclaim 2, wherein the bearing seat is formed with a plurality of screwbores, the bearing cap is formed with a plurality of through holes, andthe motorized vehicle further comprises a plurality of locking screwseach extended through a respective one of the through holes and eachscrewed into a respective one of the screw bores, thereby fixing thebearing cap on the bearing seat.
 4. The motorized vehicle in accordancewith claim 2, wherein each of the two single-direction thrust bearingsis mounted between the bearing seat and the propeller shaft.
 5. Themotorized vehicle in accordance with claim 2, wherein each of the twoends of the propeller shaft is formed with a keyway, each of the twosingle-direction thrust bearings has an inner race formed with an innerkeyway, and the motorized vehicle further comprises a first key securedin the inner keyway of each of the two single-direction thrust bearingsand the keyway of the propeller shaft, so that each of the twosingle-direction thrust bearings is combined with the propeller shaft.6. The motorized vehicle in accordance with claim 2, wherein each of thetwo single-direction thrust bearings has an outer race formed with anouter keyway, the bearing seat has two sides each formed with a keyway,and the motorized vehicle further comprises two second keys each securedin the outer keyway of a respective one of the two single-directionthrust bearings and the keyway of the bearing seat, so that each of thetwo single-direction thrust bearings is combined with the bearing seat.7. The motorized vehicle in accordance with claim 2, wherein each of thetwo ends of the propeller shaft is formed with a catch flange, one ofthe two single-direction thrust bearings is rested on and limited by thecatch flange of the propeller shaft and the bearing cap.
 8. Themotorized vehicle in accordance with claim 7, wherein the fixing memberis secured on the propeller shaft and is rested on the other one of thetwo single-direction thrust bearings.
 9. The motorized vehicle inaccordance with claim 2, wherein each of the two ends of the propellershaft is formed with an outer thread, and the fixing member is formedwith an inner thread screwed on the outer thread of the propeller shaft,so that the fixing member is fixed on the propeller shaft.
 10. Themotorized vehicle in accordance with claim 2, wherein the bearing seathas a periphery provided with a fixing board, and each of the two rearwheels is secured on the fixing board of the respective bearing seat.11. The motorized vehicle in accordance with claim 10, wherein thefixing board of the bearing seat is formed with a plurality of throughholes, each of the two rear wheels is formed with a plurality of throughholes, and the motorized vehicle further comprises a plurality oflocking bolts each extended through a respective one of the throughholes of the fixing board of the bearing seat and a respective one ofthe through holes of the respective rear wheel, so that each of the tworear wheels is fixed on the fixing board of the respective bearing seat.